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Species richness and assemblage structure of Trichoptera in Danish streams
Abstract
SUMMARY 1. Species richness and assemblages of Trichoptera from 157 'pristine' Danish lowland stream sites were analyzed, for dependence on geographical position of the sites and simple physical variables, using two way indicator species analysis and detrended correspondence analysis. 2. A total of 106 species were recorded, representing » 90% of the species pool known from Danish streams. Only seven species occurred at more than half the sites, whereas an additional 11 species were found at more than a quarter of the sites. 3. Although sites showed significant regional differences in environmental variables (stream order, width, slope and presence/absence of riparian forest), species richness and assemblages were primarily correlated with stream order, width and slope. Maximum richness was found at the largest (5th order) stream sites. 4. Regional differences in species assemblages were found, with several species being absent from the islands Funen and Bornholm. Species assemblages also differed between forested and non-forested stream sites. 5. We found evidence that stream temperature may be of only minor importance in determining Trichoptera species richness and assemblage composition in Danish streams compared to other size-related physical factors.
... The second group consists of variables that were found to be good predictors of species distribution, but do not directly influence the organisms. The "indirectly (HIGLER and VERDONSCHOT, 1992), altitude (MARCHANT et al., 1995), distance to source (BRÖNMARK et al., 1984), stream order (WIBERG-LARSEN et al., 2000;BIS et al., 1992) and land use (CORKUM, 2003;COLLIER and QUINN, 2001). Nevertheless, these findings were obtained from different regions, ranging from lowland, through hilly, to mountainous, with different ecological characteristics. ...
... Variables representing the water course size gradient and the slope gradient along streams have been shown to be good predictors of distribution of the caddis larvae and other macroinvertebrates assemblages in many studies of other European streams (WRIGHT et al., 1984;HIGLER and VERDONSCHOT, 1991;WIBERG-LARSEN et al., 2000). In our study, distance to source and stream order were the best predictors in both mountainous ecoregions of the Alps and the Dinaric western Balkans. ...
... Also BONADA et al. (2005) found out that 594 G. URBANIČ and M. J. TOMAN size dependent variables were more important than temperature in explaining longitudinal zonation of Trichoptera. WIBERG-LARSEN et al. (2000) also concluded that temperature may be of only minor importance in determining Trichoptera assemblage composition in Danish streams compared to other size related physical factors, and at least in lowlands, temperature may be less important than stream size within a single region. The relative lack of importance of temperature in determining the presence or absence of Trichoptera species in lowland regions is in concordance with our results in the Pannonian lowland ecoregion. ...
... Also, they are frequently used to investigate the effect of various variables on longitudinal distribution of aquatic macroinvertebrates (e.g. Wiberg-Larsen et al., 2000;Gombeer et al., 2011). The Hron River (Slovakia, Central Europe) was strongly polluted by urban sewage and industrial wastewaters in the middle of the 20th century and still suffers from some, albeit low, degree of pollution (Krno, 2007). ...
... Several studies demonstrated strong influence of stream size on macroinvertebrate diversity -low species richness in spring areas and its increase in the downstream direction (e.g. Wiberg-Larsen et al., 2000;Heino et al., 2005). The same diversity pattern was observed in mayfly assemblages of upstream tributaries of the Hron River (Svitok, 2006) but not in caddisfly assemblages of the same sites (Novikmec, 2005). ...
... stream width, discharge, stream order) and benthic macroinvertebrate species richness seems to be a general pattern in European streams of the first to fifth order (cf. Wiberg-Larsen et al., 2000). In our study, diversity of caddisflies was higher in the upper part of the Hron River than in the lower stretches. ...
A thorough understanding of biotic communities distribution in predistur-bance state is essential for predictions of their future changes related to human activities. In this regard, pre-damming data on spatial distribution of benthic communities are highly valuable. Caddisflies were sampled at 14 sites of the Hron River and analysed in order to establish longitudi-nal zonation of the river and to determine environmental factors affecting assemblages' distribution in the longitudinal profile. A total of 2600 indi-viduals of caddisflies belonging to 40 taxa of 12 families were recorded. Diversity of caddisflies was found to be higher in the upper (rhithral) part of the river. Major change, with shift to much more uniform caddisfly as-semblages, occurred in the middle part of the river. Four zones (subzones) were distinguished using caddisfly communities: epirhithral, metarhithral, hyporhithral and epipotamal. Canonical correspondence analysis demon-strated the determining influence of altitude and conductivity on the cad-disflies. Pre-damming zonation patterns presented here could serve as basic information for management of the Hron River as well as a reference scheme for other, previously dammed big rivers in the West Carpathian region. RÉSUMÉ
... The specific interplay of various environmental factors operating at different spatial and temporal scales is generally considered to determine the composition and structure of aquatic insects communities (e.g., GILLER and MALMQVIST, 1998;WIBERG-LARSEN et al., 2000). Temperature, oxygen content, the current-substrate relation, nutrient composition and availability, and habitat cover are some of the most important factors influencing aquatic organisms (GILLER and MALMQVIST, 1998;MOOG, 2002). ...
... In addition, competition for food and space, predation or prey distribution may influence the abundance and distribution of aquatic insects (GEORGIAN and WALLACE, 1981;MERRITT and WALLACE, 1981;MINSHALL, 1984). The influence of macrophytes on the composition and abundance of macroinvertebrate taxa is well known, since macrophytes contribute significantly to the habitat diversity (WIBERG-LARSEN et al., 2000;ROSI-MARSHALL and WALLACE, 2002). More specifically, macrophytes influence hydraulic roughness, water depth, flow velocity, and reduce predation, provide food and refuge and generate oxygenated environments (MILIŠA et al., 2006a;GOLUBIĆ et al., 2008;BAZZANTI et al., 2010;SCHEIBLER and CIOCCO, 2011). ...
... More specifically, macrophytes influence hydraulic roughness, water depth, flow velocity, and reduce predation, provide food and refuge and generate oxygenated environments (MILIŠA et al., 2006a;GOLUBIĆ et al., 2008;BAZZANTI et al., 2010;SCHEIBLER and CIOCCO, 2011). Water course size and slope gradient along streams have been shown to be good predictors of the distribution of caddis larvae and other macroinvertebrate assemblages (WIBERG-LARSEN et al., 2000). Generally, habitat heterogeneity is essential for invertebrate species richness and community structure, offering a great number of niches and refugia from disturbance and predation (BEISEL et al., 2000). ...
The caddisfly community composition in different microhabitats at tufa barriers was studied in the
Plitvice Lakes NP, Croatia. Three tufa barriers were investigated and six emergence traps were installed
at each site covering various microhabitats. Sampling was conducted monthly during the year 2008.
Tufa barriers are lake outlet habitats, but they feature a variety of microhabitats similar to streams, which
is reflected in the composition of caddisfly communities regarding longitudinal distribution preferences.
The caddisfly communities at all three sites were dominated by species typical for the rhithral zone,
but there was a shift in species composition along a longitudinal gradient, from the epirhithral to the
metarhithral zone. Analysis of functional feeding guilds showed considerable differences between the
caddisfly community at the Labudovac barrier and both downstream barriers, shifting from one with a
quite diverse composition, to one completely dominated by passive filter-feeders. Passive filter feeders
were not represented by the same taxa at up- and downstream barriers (i.e., by Hydropsyche species and
Wormaldia species, at the Labudovac barrier and at both downstream barriers, respectively). Due to high
complexity and habitat diversity, the highest diversity and equitability of caddisfly communities were
recorded at microhabitats with particulate tufa and medium current velocity (10–20 cm/s). The lowest
diversity and species richness were recorded for silt with low current velocity (0–10 cm/s). Abundance
of caddisflies was positively correlated with current velocity due to a very high proportion of rheophilic
passive filter feeders in the communities. However, community composition and structure is only to
some degree influenced by microhabitat characteristics, but rather by their general position within the
barrage-lake system, i.e., longitudinal distribution and thereby availability of different food resources.
... However, in aquatic communities, the support for bimodal core-satellite pattern is relatively weak and the unimodal-satellite-dominant pattern seems to be more common (Tokeshi 1992;Heino 2008Heino , 2015Verberk et al. 2010;Korkeamäki et al. 2018;Renner et al. 2020). For example, Jenkins (2011) re-analysed two freshwater macroinvertebrate datasets (Wiberg-Larsen et al. 2000;Oertli et al. 2008) and he found unimodal-satellite SOFD pattern in both cases. ...
... Most previous SOFD studies have, however, focused on single taxonomic group in aquatic macroinvertebrate assemblages, such as chironomids (Diptera: Chironomidae) (Tokeshi 1992), caddisflies (Trichoptera) (Wiberg-Larsen et al. 2000) and damselflies and dragonflies (Odonata) (Korkeamäki et al. 2018;Renner et al. 2020), or combined data several macroinvertebrate taxonomic groups together (Heino 2008(Heino , 2015Verberk et al. 2010; see also Jenkins 2011). Therefore, it was not clear whether several species groups in aquatic invertebrate communities would produce unimodal-satellite SOFD pattern or whether there is variation between taxonomic groups in the SOFD patterns in a regional scale. ...
Metacommunity models describe species occupancy frequency distribution (hereinafter ‘SOFD’). Our goal is to present how the differences in eight macroinvertebrate orders dispersal ability affect SOFD patterns. A total of 293 species from eight macroinvertebrate orders were observed in 14 eutrophic lakes in southern Finland. Species occupancy ranged from 1 to 14. About 30% (89 out of 293) of the species were found in only one lake, yielding a surprisingly high number of rare species. So, there were few widely distributed common species and numerous rare species with a restricted distribution. Combined data from eight macroinvertebrate orders supported the bimodal truncated SOFD pattern. Similarly, the low dispersal ability orders, watermites and mayflies, fitted the bimodal truncated SOFD pattern. However, bimodal symmetric SOFD pattern also fitted relatively well to the dragonflies and damselflies with high dispersal ability. It seems that differences in dispersal ability among different macroinvertebrate orders may partly explain observed differences. Moreover, our results supported slightly more a niche-based model rather than a metapopulation dynamics model in eutrophic lakes littoral macroinvertebrate metacommunities. Our results highlight that the dispersal ability is important trait for species conservation in patchily distributed habitat.
... A variety of fish other than salmonids inhabit these downstream reaches, which have a rich bird life too. A survey of Danish lowland streams (Wiberg et al. 2000) has shown that the number of caddis fly species increases considerably from the headwaters to the lowermost floodplain streams. This gradual downstream increase is probably related to the greater availability of habitats rather than to the size of the streams. ...
... odplains, however, need not to be permanent. In straightened and deepened streams, a recovery from the disturbance is at work from the very beginning. When the Skjern Å river channel was abandoned in the year 2000, traces of riffle and pools appeared in the dry bedthey had evolved in less than 40 years. And a very diverse insect life had developed (Wiberg-Larsen et. al 2000). ...
... In our study, 2 caddisfly species were recorded in the spring and the dominance of Apatania muliebris was recognized. Our findings correspond with some earlier studies that have shown the occurrence of the grazer Apatania muliebris in unshaded, cool springbrooks with permanent water temperature and occasionally dense epilithic microalgal cover (Nógrádi 1994, Wiberg-Larsen et al. 2000, Nógrádi & Uherkovich 2002. ...
... According to the CCA results, sampling sites and their typical habitats are ordered along the gradient of slope and water velocity. As shown in numerous studies, the slope related to stream velocity gives one of the best approximations for the composition of stream benthic macroinvertebrate communities (Malmqvist & Maki 1994, Malmqvist & Hoffsten 2000, Wiberg-Larsen et al. 2000. Water velocity represents a direct force to the organisms, influencing also other in-stream factors such as substratum composition, and oxygen content (Sandin 2003). ...
In 2006–2007 larval caddisfly assemblages of a semi-natural calcareous stream (Örvényesi Creek) were studied. Characteristic sections can be detected along the whole length of the stream, which passes through diverse types of vegetation, resulting in highly heterogeneous aquatic habitats. Based on an annual survey of different aquatic habitats, our aims were to give an overview of the spatio-temporal distribution of the larval caddisfly assemblages in the Örvényesi Creek and to find indicator species characterizing different sections of the stream. In order to show the spatio-temporal patterns, samples were collected at 7 locations with different streambed morphology, from spring to the mouth of the stream. Caddisfly larvae were collected in every 3rd week during a 1 year period using the " kick and sweep " method. Multivariate analyses were carried out to explore the spatio-temporal structure of caddisfly assemblages. The indicator value method was applied to detect indicator species for different sections of the stream. A rich caddisfly fauna (20 taxa) was found in the Örvényesi Creek. Fast-running and relatively cold-water hypocrenal sections were characterized by Beraea maurus and Apatania muliebris at high indicator value. Three Limnephilidae species (Limnephilus rhombicus, Limnephilus lunatus and Glyphotaelius pellucidus) were identified as significant indicator species for slow flowing, lentic habitats. Along the length of the stream, distinctive spatial and temporal changes were detected in the distribution of the caddisfly assemblages. These changes were mainly connected to variations in morphology of the streambed, phenology of individual taxa, extreme weather conditions and human impacts.
... A variety of fish other than salmonids inhabit these downstream reaches, which have a rich bird life too. A survey of Danish lowland streams (Wiberg et al. 2000) has shown that the number of caddis fly species increases considerably from the headwaters to the lowermost floodplain streams. This gradual downstream increase is probably related to the greater availability of habitats rather than to the size of the streams. ...
... plains, however, need not to be permanent. In straightened and deepened streams, a recovery from the disturbance is at work from the very beginning. When the Skjern Å river channel was abandoned in the year 2000, traces of riffle and pools appeared in the dry bed -they had evolved in less than 40 years. And a very diverse insect life had developed (Wiberg-Larsen et. al 2000). The methods of traditional stream management often led to situations where streams were prevented from making their own recovery. Riffles were regularly dredged and banks reinforced to prevent meandering. Macrophytes were cut, thus preventing these ecological engineers from raising the water table and assisting the current in reshaping ...
... At a more local scale and for unimpaired streams and rivers, the most influential environmental factors appear to be associated with stream morphology (stream order, altitude, bed width, etc.) and hydrology (e.g. flow velocity), as shown by numerous studies (Wiberg-Larsen et al., 2000;Resh, Reynoldson & Rosenberg, 2002;Feio et al., 2005). In contrast, in some possibly degraded watercourses water chemistry, particularly pH and water hardness, may play a major role (Ormerod & Edwards, 1987;Lock & Goethals, 2012). ...
1. Community patterns are generated by multiple processes and constraints generated at different spatial and temporal scales. 2. A large-scale study was carried out on the Trichoptera of four Algerian regions with contrasting climates, vegetation cover, and human pressures. 3. Overall, 22 identified taxa were recorded, including nine families and 14 genera. The genus Hydropsyche was represented by eight species, with Hydropsyche maroccana and Hydropsyche lobata being the most abundant species. 4. With one exception, localities in the subhumid Collo and the high-altitude Batna were the most species rich, whereas localities in the semi-arid Oum el Bouaghi were the most species poor. 5. Nonmetric multidimensional scaling (NMDS) separated the caddisflies recorded into four assemblages organized by a set of constraining environmental factors (land use, altitude, water depth, helophyte cover, and flow velocity gradients) acting at different scales. 6. As inadequate knowledge of insect biodiversity is a major limitation to their conservation, this article discusses how these results might help predict caddisfly communities in adjacent regions and enhance conservation efforts.
K E Y W O R D S caddisflies, community ecology, conservation, freshwater biodiversity, Maghreb, Mediterranean basin, multivariate analysis, taxonomy
... Czech Republic: Adámek (1977), Chvojka (2008), Chvojka & Komzák (2006, Chvojka & Nóvak (2001), Klapálek (1890Klapálek ( , 1891Klapálek ( , 1897, Komzák & Chvojka (2012, Macek et al. (2019), McLachlan (1879), Novák (1962, 1996, Obr (1984), Sedlák (1967Sedlák ( , 2001, Skála et al. (2019), Soldán et al. (2001), Sukop (2008). Denmark: Gørtz (1998), Lindegaard & Thorup (1975), Moth Iversen et al. (1978, Thorup & Lindegaard (1977), Wiberg-Larsen et al. (2000). Estonia: Timm, personal communication, Viidalepp et al. (2011). ...
The presence and distribution of Rhyacophila fasciata Hagen 1859 in Europe were revised, based on bibliographic study, collection specimens, and new material collected in different countries. The status of formerly synonymized species, Rhyacophila ferruginea (Scopoli 1763) and Rhyacophila septentrionis McLachlan 1865 was also assessed. The type of R. ferruginea is missing, the taxon is still unidentified, and thus we propose Rhyacophila ferruginea as a nomen dubium. Morphological features and genetic evidence revealed that R. septentrionis differs from R. fasciata, so we propose to change its status to status resurrectus. We therefore include new descriptions of the different stages (larva, pupa, male, and female) of R. fasciata and of R. septentrionis, together with a molecular analysis based on mitochondrial cytochrome oxidase I (mtCOI) and ecological notes. The species R. coppai Oláh 2020 NEW SYNONYM and R. soreda Coppa & Oláh 2020 NEW SYNONYM are synonyms of R. sociata Navás 1916; the species R. kopasa Oláh & Coppa 2020 NEW SYNONYM and R. rova Oláh & Coppa 2020 NEW SYNONYM are synonyms of R. denticulata McLachlan 1879; the species R. matrensis Oláh & Szczęsny 2020 is probably a synonym of R. fasciata, so more study of this species is needed in order to confirm or deny that it is a valid species.
... and therefore possibly has greater habitat complexity (Vinson and Hawkins, 2002) and variation in substratum (from sandy, sediment to rocks) (e.g. Gehrke and Harris, 2000;Wiberg-Larsen et al., 2003), thus able to support greater diversity (Oberdoff et al., 1995). Furthermore, the KRBAP has a larger potential source population in the upstream reservoir as there are no barriers to prevent movement of fish when water is released (Fig. 4). ...
A 2.7-km canalised section of the Kallang River, a major storm-water drain and reservoir spillway in Singapore, was rehabilitated into a 3-km naturalised, meandering river between 2009 and 2011. A combination of plants, natural materials, and civil engineering techniques were introduced to soften the edges of the waterway, to give it a more natural appearance and prevent soil erosion. Baseline data and published evidence of enhancement of aquatic biodiversity in this naturalised urban waterway are lacking, as there have not been any comprehensive biological surveys of the system to date. To determine the effect of rehabilitation, we quantitatively compared the fish assemblage and abiotic variables in the Kallang River after its rehabilitation (re-named Kallang River at Bishan-Ang Mo Kio Park or KRBAP; 2016–2018) against a downstream unrehabilitated section of the river (Kallang Canal; 2012). Secondly, we qualitatively compared fish assemblages and abiotic variables at the KRBAP and the Kallang Canal, to their source (upstream) reservoir, as well as to natural forest streams in close proximity. The KRBAP has a unique fish assemblage, which is dominated by two non-native cichlid taxa (quetzal cichlid, Vieja melanura (68%) and tilapia, Oreochromis spp. (17%)). Fish species richness (p < 0.001) and the percentage of native species (p = 0.015) was significantly higher in the KRBAP compared to the unrehabilitated canal. Moreover, the abiotic variables at the two sites are also significantly different. The fish assemblage and abiotic variables at the KRBAP resemble those of its (upstream) source reservoir, but contrasts with those of nearby natural forest streams. The unique fish assemblage in the KRBAP is shown to be stable, with similar species captured in high abundances across the three sampling years post-rehabilitation. Given the stability within the rehabilitated stream, further research and monitoring are needed to determine the established food web and predict the possible influence of future non-native species additions.
... Ecological features. The biodiversity of the caddisfly fauna at the study localities is conditioned by their biological characteristics, the diversity of microhabitats important for larval stages, as well as the hydrological characteristics of a certain locality (Habdija et al. 2002(Habdija et al. , 2004Svensson 1972;Šemnički et al. 2012;Urbanič et al. 2005;Waringer 1991;Wiberg-Larsen et al. 2000). ...
Caddisfly faunistic and ecological features were studied at 14 sampling sites along the catchment area of the Dobra River. Adults were collected monthly, over a period of 13 months (from early November 2009 until the end of November 2010), using ultraviolet (UV) light trap and entomological net. Physico-chemical parameters of water and air were also measured at all sampling sites. The study encompassed several segments of caddisfly fauna: the composition, new records, the distribution of all recorded species and seasonal dynamics. A total number of 77 species were recorded, out of which 15 species and four genera were new records for Croatian caddisfly fauna. The CCA analysis showed that the water temperature and the altitude had the highest impact on the distribution of caddisfly fauna in this area. The results of this study contribute to the increase of faunistic and ecological knowledge of the Croatian caddisflies.
... However, studies of longitudinal zonation along the same water course from mountain headwaters to lowland river may obscure the effect of altitude itself because small streams and large rivers, even at the same altitude, represent different habitat types (e.g. Finn et al., 2011;Richardson, 2019), and because stream size itself influences taxon richness (Brönmark et al., 1984;Malmqvist and Hoffsten, 2000;Wiberg-Larsen et al., 2000). As opposed to longitudinal studies, clear relationships between community parameters and altitude are usually not observed in multi-stream studies of e.g. ...
We collected quantitative macroinvertebrate samples and measured environmental and geographical parameters at 13 sites: six along the main stem and seven in tributaries close to the main channel over a 700 m gradient in altitude and 22 km longitudinal distance along the River Kokra in the Slovenian Alps. Our objectives were 1) to compare longitudinal patterns in richness and community composition between main stem and tributary sites, and 2) to determine the relative importance of the replacement and richness difference component for overall beta diversity and of environmental versus spatial distance on beta diversity among main stem and tributary sites.
In total 138 taxa were identified. There were no differences between main stem and tributary sites in mean abundance or taxon richness (67 and 58, respectively). A nMDS and ANOSIM based on Bray-Curtis similarities found no separation of main stem and tributary sites, but that upper (≥880 m a.s.l) and lower sites (≤680 m a.s.l.) formed two different groups. In both main stem and tributaries taxon richness increased only slightly going downstream while the community composition (DCA1) was much better explained by altitude and distance from source.
Overall, beta diversity (Sørensen and Bray-Curtis dissimilarity) was similar for the two groups, and total Sørensen dissimilarity was driven mainly by replacement in main stem (78 %) and tributary sites (77 %). Mantel tests showed that main stem dissimilarities were significantly correlated to environmental PCA distance, watercourse distance, overland distance and altitudinal differences. Tributary dissimilarities were not correlated to any of these four factors. GLMs showed that dissimilarity among main stem sites was explained only by altitude difference, while no factors were significant among tributary sites, even though nearly so for environmental PCA distance.
The study illustrates the importance of measuring beta diversity along ecological gradients, such as river continua and/or altitudinal gradients, where alpha diversity may fail to detect relatively minor changes in assemblage composition. Such changes are likely to occur due to present and future climate warming.
... Headwater streams in mountain areas have low temperature, high gradient and are often bordered by riparian forest. In downstream, the temperature increases, gradient decreases and the importance of shading from riparian canopy declines enabling aquatic macrophytes to develop (Larsen et al., 2000). Temperature has an overall influence on life processes and may play a major role in controlling composition, development and function of Ephemeroptera, Plecoptera and Trichoptera taxa in hill stream of south India (Dinakaran and Anbalagan, 2007b). ...
We examined the effect of two dominant leaf litter species of Pongamia pinnata and Syzygium cuminii on the colonization of macroinvertebrate community in a tropical stream of south India. The result of the leaf fall pattern of stream revealed that leaves entering regularly in to the stream for a year, and a greater proportion of leaves
occurred between January and June. Out of 4 riparian vegetation features, tree shade and abundance of S. cuminii were significant predictors of macroinvertebrate assemblage variation The rate of colonization of macroinvertebrates was higher in S. cuminii than P. pinnata. Assemblages were composed of collector- filterers (38.3%), and to a lesser extent predators (36.5%) and collector-gatherers (23.4%). Of the 12 environmental variables, water temperature, pH and stream substrates were the significant predictors of macroinvertebrates assemblage colonization.
... The individual variables are plotted in Figure 2b while the 2 gradients created by these environmental variables are visualized in Figure 2a; one vegetationrelated gradient from the presence of submerged vegetation towards an important percentage-shadecover by adjacent trees, and a second size-related gradient from larger, higher order streams towards sources and upper-stream sections. Both gradients are known to be important in shaping Trichoptera species assemblages (Wiberg-Larsen et al. 2000, Arscott et al. 2003, Bonada et al. 2005, Urbanič & Toman 2007. ...
Flanders is a very densely populated region in the economic heart of Europe. To monitor the anthropological impact on the biological integrity of the freshwater courses, the Flemish Environment Agency (VMM) uses the Multimetric Macroinvertebrate Index for Flanders (Gabriels et al. 2006) which was recently developed under the influence of the European Water Framework Directive (WFD, EU 2000). This multimetric tool replaces the Belgian Biotic Index (BBI: range 0=dramatically poor quality to 10=very good quality), a monitoring system based on the sensitivities to pollution of the different macroinvertebrate taxa (De Pauw & Vanhooren 1983, De Pauw et al. 1986). Although recently replaced, the BBI has been used for the past 20 years and this extensive monitoring campaign produced a considerable amount of information on the distribution of macroinvertebrate taxa in Flemish freshwater courses. The Trichoptera (caddisflies) constitute one of these taxa. Unfortunately, determinations of caddisflies as part of the BBI monitoring, are accomplished only at the family level. Specific information on the occurrence and ecological preferences at the species level is scarce and outdated. The only comprehensive report documenting the occurrence of Trichoptera in Belgium dates back to 1984 (Stroot 1984) and since then only minor revisions and additions to the original report have been published (Stroot 1985, 1987; Stroot & Neven 1989). Therefore, the objectives of our research are to update the old species records and to elaborate and improve the ecological and phylogenetic knowledge of the Flemish Trichoptera by (a) identifying the caddisfly species that occur in Flanders; (b) determining their present distribution; (c) detecting which environmental variables influence this distribution; (d) studying whether the relationship among these variables and the species assemblages can be used to distinguish among the ecoregions in Flanders, which are based on similarities in climate, geology, geomorphology, (geo)hydrology and soil characteristics (Sevenant et al. 2002) and (e) investigating the phylogenetic relationships among the Flemish Trichoptera and evaluating their accordance with the current taxonomic classification.
... According GALDEAN et al. (2000), evaluation of habitat diversity is an important tool in health approach to aquatic ecosystems due to the strong relationship between availability of habitats and aquatic Urban streams are subject to a "cocktail" of anthropogenic stressors, impacts and contaminants. Macroinvertebrate assemblages respond to combinations of environmental (e.g., abiotic factors such as flow and substratum) and pressure drivers that may act together or in isolation (WIBERG-LARSEN et al., 2000). The "habitat template" theory proposes that temporal and spatial variability in physical habitats influence the evolution of physical, behavioural, and physiological species profiles (SOUTHWOOD, 1977). ...
Aquatic ecosystems are under severe anthropogenic modifications. Thus, the dependent biological communities in these environments are also changed. The objective of this study was to investigate the effects of urban development in a highly impacted ecosystem. We selected 15 sampling points along the stream Ribeirão Vermelho, in which were sampled benthic macroinvertebrates and assessed the water and habitat diversity. It was found an impact gradient, with some the reference points classified as natural and others as impacted. There was a significant difference in all biological indicators used. The total number of taxa, the wealth of Diptera, the taxa Ephemeroptera, Plecoptera and Trichoptera, and the diversity indices, the Water Quality Indices, and the percentage of herbivores crushers and predators were significantly higher in points classified as natural and changed. The relative abundances of collectors, filter feeding, chironomids and parasites were significantly lower in sites classified as natural in relation to impacted ones. The metrics of the macroinvertebrate community benthic and Habitat Diversity Protocol were influenced by environmental degradation, being a useful tool for planning and development actions for the preservation of watersheds and the prioritization of high-value transmission systems for protection and rehabilitation of aquatic ecosystems
... The effects were not observed for the adult caddisflies in the stream. In contrast, several examples of research on physico-chemical factors have been done with adults in Europe (Wiberg-Larsen et al. 2000), North America (Ross 1963), South Africa (de Moor 1993) and Nigeria (Ogbogu 2001(Ogbogu , 2006(Ogbogu , 2009). Hence, this study was conducted to investigate the abundance and diversity of adult caddisflies in the Opa River and the effect of certain water quality parameters on the abundance and distribution of the caddisflies species. ...
The species composition and abundance of caddisflies in association with some water quality parameters (pH, water temperature and conductivity) in Opa Stream in Ile-Ife, Nigeria were investigated during October 2009–August 2010. One hundred and ninety adult caddisflies collected from the stream represent six species in six genera and three families. Hydropsychidae had three species, which is more than were found in other families. The caddisflies showed a relative mean abundance of 62% and 38.9% in the wet and dry seasons, respectively. Caddisfly abundance was positively correlated with pH and conductivity but there was a negative relationship between water temperature and the abundance of caddisflies in the stream.
... Caddisflies are an order rich in families that have developed adaptations to the conditions in which they occur. Representatives of the case-building caddisfly families such as Goeridae and the net-spinning caddisflies such as Hydropsychidae are present in lotic environments, while other families, such as Molannidae and Phryganeidae, are characteristic of lentic environments [39,40]. Limnephilidae, which is considered the most common caddisfly family, includes cosmopolitan taxa from both environments [41]. ...
Biodiversity is a significant element that describes the ecological state of waterbodies. Eutrophication is a widespread problem that has an impact on water habitats and leads to the succession of sensitive species. Habitat degradation results in significant, predictable decreases in taxonomic diversity. We assessed benthic macroinvertebrate community structure (mainly families) in 9 rivers, 9 ponds, and 23 lakes in northeastern Poland. Mollusca, Annelida, Arthropoda, and Nemathelminthes were the 4 phyla represented, and 76 Insecta families, 5 taxa of Crustacea, and 12 Mollusca families were identified. A total of 91 taxa (mainly families) were recorded in all of the waterbodies studied. Diptera, Trichoptera, Ephemeroptera, and Gastropoda were the major components of the benthic macroinvertebrate communities in the aquatic habitats studied. The biodiversity values of the macroinvertebrate assemblages in the rivers and lakes studied were similar. This likely resulted from the similar number of habitats in both types of waters. Differences in biodiversity among the various waterbodies could be evidence of the moderate, diversified anthropogenic pressure to which they are subjected. The analysis of similarities indicated that in terms of the benthic macroinvertebrate communities, the waterbodies studied formed three groups, which, with just one exception, consisted separately of rivers, ponds, and lakes.
... Although less important from a quantitative point of view, other caddisflies (Philopotamus montanus, Wormaldia occipitalis) and few gastropods (Bythinella schmidti and Sadleriana sp.) show a marked habitat-specific preference for crenic conditions (Stoch, 2001;Wiberg-Larsen et al., 2000). ...
Springs are important environments between hypogean and epigean habitats; the interaction between aquatic and terrestrial ecosystems is an important factor for their biotic communities. We investigated the ecology of the macrobenthic community of two lowland springs in the River Ticino valley, focusing on the autoecology of some relevant species and on the role of springs as hotspots of biodiversity in an area threatened by anthropogenic pressure. We collected 26 taxa in total: diptera (8), trichoptera (6), gastropods (5), coleoptera (2), crustacea (2), lumbricidae (1), odonata (1), plathelminthes (1). Some of them are stenothermal and oligotrophic species thus quite unusual for a flood plain area characterized by intensive agricultural activities. In conclusion, our study highlights the importance of lowland springs in conserving some habitat-selective macrobenthic species.
... As the majority of stonefly species prefer the headwaters of lotic habitats (Graf et al., 2003(Graf et al., , 2009(Graf et al., , 2017, taxa richness generally decreased downstream as expected and supported by preliminary studies (Vannote et al., 1980;Sivec, 2009, 2011b). The exception was Plitvica Stream, which supported a higher taxa diversity due to its high microhabitat heterogeneity (Waringer, 1996;Wiberg-Larsen et al., 2000) and the availability of various food resources (Miliša et al., 2006;Špoljar et al., 2007;Vilenica et al., 2017aVilenica et al., , 2017b. As expected for karst hydrosystem, the assemblage structure showed a downstream longitudinal shift from domination of crenal-epirhithral elements to domination of epirhithral-metarhithral with some hyporhithral and potamal elements. ...
Stoneflies are among the most sensitive aquatic insect taxa and therefore arguably the best indicator of the excellent, i.e. pristine, ecological status of surface streams. Karst habitats are one of the most exciting freshwater habitats in terms of biological-geological interplay. They, in turn, support a biodiversity far superior to surrounding freshwater habitats and hence these habitats are designated as biodiversity hotspots. Our study deals with both of these crucial ecological players. We studied stonefly assemblages, their microhabitat preferences and emergence patterns along a karst oligotrophic hydrosystem. The sampling was conducted monthly from March 2007 to December 2008 using pyramid-type emergence traps set in various habitats and associated microhabitats (e.g. springs, rivers, streams, tufa barriers × moss, angiosperm, cobble, sand, silt substrates). Favorable environmental conditions, such as a wide range of karst habitat types with low water temperature and high oxygen concentration, resulted in high stonefly species richness (31 recorded species). Water temperature and pH had the highest influence on stonefly assemblages. Species richness and diversity decreased in a downstream direction. We recorded a longitudinal shift from crenal-epirhithral to epirhithral-metarhithral assemblages with some hyporhithral and potamal elements. Upstream sites were dominated by shredders, while downstream sites had a higher proportion of gatherers-collectors. Several species showed a significant preference for a specific microhabitat type in accordance with their feeding strategies and food availability. The majority of recorded species exhibited univoltine life cycles slow or fast.
... All the previously mentioned results indicate that micro-habitat diversity (springs, streams, 16 lakes, tufa barriers) and water quality have a dominant influence on the faunal biodiversity of a certain area (Waringer, 1996;Wiberg Larsen et al., 2000;Kučinić, 2002;Vilenica et al., 2017aVilenica et al., , 2017b. These characteristics, which cannot be found in any other area in Croatia, make the Plitvice Lakes NP very specific area, resulting with very high caddisfly biodiversity observed in our studies. ...
The Plitvice Lakes National Park is a unique area in the world with a great variety of aquatic habitats, including tufa barriers. UNESCO has protected this area since 1979. In this paper, detailed faunistic results of the first research on Trichoptera species conducted from 1997 to 2001 are shown. Sampling was done using both light and emergence traps, and 77 caddisfly species were determined using the two methods. Furthermore, a brief overview of the Trichoptera research history in the Plitvice Lakes area is given along with a detailed presentation of caddisfly fauna and an extended second checklist of Trichoptera species in the NP. In the Plitvice Lakes 89 Trichoptera species have been recorded so far. Flight periods are given for each species. Also, the reasons of such a high degree of Trichoptera biodiversity (the highest in Croatia) in the Plitvice Lakes are highlighted. A comparison of species assemblages collected from the 12 localities was made along with the comparison of Trichoptera fauna composition in different aquatic habitats in the Plitvice Lakes NP: springs, streams, lakes and tufa barriers.
... Conversely, Ecclisopteryx dalecarlica practically disappeared from the most affected site below the PSHP Čierny Váh. The species usually inhabits the unshaded areas with microalgal epilithic growths (Wiberg-Larsen et al. 2000). Results of a potential climatic change predicted a dramatic shift in altitudinal occurrence of E. dalecarlica, as a consequence of water temperature increase (Domisch et al. 2011). ...
In spite of many investigations about the impact of reservoirs on river continuum, the downstream effects of a pumped-storage hydropower plants (PSHP) still have been less known. The aim of the study was to evaluate the downstream effect of the PSHP Čierny Váh in regard to the Serial Discontinuity Concept assumptions or studies assessing more frequent types of hydropower reservoirs. We predicted that the increase of water temperature and the alteration of food sources will hierarchically be the most relevant factors determining macroinvertebrate community composition. We focused on mayflies, caddisflies and non-insect benthic invertebrates due to their appropriate responses to discontinuity. We also determined the influence of the hydropower plant on life cycles and productions of the most abundant species of mayflies and caddisflies. We recorded the unique effect of the PSHP Čierny Váh on its downstream environmental variables. According to the nested ANOVA results, temperature regime, transported organic matter, benthic fine particulate organic matter and periphyton biomass were the environmental variables significantly modified by the river discontinuum. Significant differences were also found in the case of macroinvertebrate species richness, density and diversity. Nevertheless, based on the forward selection test for predictor effects, none of the environmental variables affected the macroinvertebrate assemblages significantly. However, the redundancy analysis revealed a separated group of macroinvertebrates preferring conditions characteristic for the site immediately below the reservoir. Regarding the impact of the reservoir on life histories, we revealed the shift in hatching, emergence and duration of life cycles of the abundant mayflies (except
... p = 0.0432) in 2010. Nevertheless, variables measured in our research did not seem sufficient to account for all the observed differences in the EPT assemblages the influence of stream hydromorphological characteristics, which are frequently related to caddisfly distribution suggesting some unmeasured stressors (Higler and Verdonschot, 1991;Wiberg-Larsen et al., 2000). The EPT and OCH indices indicate the balance of the community, since EPT are considered to be more sensitive and Oligochaeta and Chironomidae less sensitive to environmental stress (Plafkin et al., 1989). ...
... It is expected that Munzur Stream has a higher biodiversity value than Aunca and Kodi Creeks because of the size of this stream is greater than the others. There is a positive correlation between the stream size related variables and Trichoptera species richness [39]. ...
Abstract: The aim of this study was to determine the water quality of Kargı Stream, Antalya, Turkey, in terms of physical and chemical
parameters and biotic indices. For this purpose, macrozoobenthic invertebrates and water samples were taken from each of the
selected seven stations seasonally. The Belgian Biotic Index, BMWP and ASPT indices, and species diversity indices were applied for
determining the water quality by using the ASTERICS software program. With the identification of the collected organisms, a total of
126 taxa including 4 taxa from Gastropoda, 5 taxa from Oligochaeta, 1 taxon from Malacostraca, 84 taxa from Insecta, and 32 taxa from
Arachnida were detected. Stations were clustered by using UPGMA, based on organisms. Station 7 in the estuarine zone was the most
different one for the macrozoobenthic invertebrates. The lowest species diversity values were also found at this station. The water quality
of Kargı Stream was unpolluted/slightly polluted. Considering the physical and chemical parameters, biotic indices revealed changes in
the pollution load of the study area with some deviations. It is thought that the reason for these deviations was not taking into account
the geomorphological and ecological characteristics of Turkey in the biotic indices used in the current study.
... Stream-dwelling macroinvertebrates are generally distributed along environmental factors that operate at different spatial scales (Minshall and Robinson, 1998;Wiberg-Larsen et al. 2000). Such scales include geographical regions, river catchment, stream segments, and reaches. ...
Distributional data for 100 stonefly species from more than 400 sites and the corresponding species – environment relationships were examined using Canonical Correspodence Analysis. Four regions in various river basins of Slovakia were confirmed: Tatran, East-Carpathian, Danubian, and the Central-Carpathian regions. The most important factors determining distribution of stoneflies in these river basins are: vertical range of river basin, geographical region, and contact of river basin with the Vistula, the Tisza, and the Danube rivers. Fifteen groups of stonefly are associated to characteristic habitats.
... At site 2 we recorded the highest proportion of grazers/scrapers, which usually occur in unshaded streams with supposed high amount of microscopic epilithic algae (Wiberg- Larsen et al. 2000). The second highest proportion was at site 7, which is situated in an open area like the most impacted sites 4 and 5, where the proportion of this feeding type was lower, but unlike them it was not so affected by erosion due to shallow vee. ...
Hydrobiological research of high mountain streams in the High Tatras was carried out in 2009–2010. We evaluated the influence of windstorm on caddisfly assemblages. To assess the influence of windstorm we focused on river morphology using the RHS method and evaluation of TAM, TOM and BOM (CPOM, FPOM, UFPOM) amount in seven streams. Site 1 was a control and the other six were disturbed by the windstorm in different ways. The most remarkable differences compared to the control site was in feeding structure at sites most affected by erosion. In these streams there was a noticeable dominance of predators from the family Rhyacophilidae (mainly Rhyacophila tristis; sites 3, 4, 5, 6) and a remarkable decrease of passive filter feeders (site 4, 5). Using Spearman coefficient we confirmed a positive correlation between the proportion of predators and amount of TAM caused by erosion of steep deforested slopes of windstorm affected sites. In contrast, we did not observe such an increase in the proportion of predators at site 7, which was affected by both windstorm and subsequently by fire. This might be explained by the shallow vee valley with no observed erosion, where this site is situated. We also found a negative correlation between predators and evenness, indicating unstable community structure clearing succesion in the streams disturbed by erosion, and a negative correlation between passive filter feeders and UFPOM. We found out that overhanging tree boughs and LWD had an influence on species composition. RHS was a useful tool in characterising the influence of hydromorphology on caddisfly assemblages.
... La tolerancia térmica y osmótica de tricópteros y efemerópteros, como grupos, es más amplia comparada con la de plecópteros, ya que algunos taxones están adaptados para medrar en aguas leníticas, cálidas y/o salobres e incluso athalasohalinas, aunque la mayor parte de las familias pertenecientes a estos grupos suelen distribuirse en aguas dulces, corrientes y relativamente frías (Williams & Felmate, 1992;Wiggins, 1996;Tachet et al., 2000). La distribución de tricópteros ha sido también relacionada con la magnitud y calidad de la cubierta vegetal riparia (Wiberg-Larsen et al., 2000). En la región estudiada, la calidad y grado de cobertura de la vegetación de ribera resultó bastante dependiente del gradiente salinidad-termicidad (Suárez et al., este volumen) por lo que ambos factores podrían solaparse aquí para determinar la distribución observada para este grupo de familias, y probablemente de otras. ...
Macroinvertebrates and selected physico-chemical characteristics (temperature, pH, basin area, stream order, altitude, discharge, conductivity, ammonium, nitrites, nitrates, phosphates) were studied in 157 sites distributed over 12 Mediterranean fluvial basins located in the Iberian Peninsula and in the island of Majorca. A total of 127 taxa were recorded, mostly identified to the taxonomic resolution of family. Correspondence analysis (CA) and canonical correspondence analysis (CCA) were used to explore the tendencies of variation of the abundances of different families and their relationships with physico-chemical variables. The selected environmental variables explained more than half of the pure variance of the data matrix of families on the three first canonical axes. Salinity and temperature were the main variables explaining the distribution of families. These variables formed a natural gradient which was negatively correlated with altitude and discharge. The most halo-thermophilous families, according to this ordination, were Thiaridae and Ephydridae, followed by crustaceans, Odonata, Coleoptera and Heteroptera (OCH). Stoneflies were the group of families favouring narrow ranges of the lower values of temperature and salinity, followed by mayflies and caddisflies. A second environmental gradient was chiefly correlated with discharge. However, the gradient was also related with temporality of the aquatic habitat. In this second gradient it was difficult to separate the natural regime from anthropogenic disturbances. Organic pollution was associated with the third emerging gradient. Asellidae, Syrphidae, Chironomidae and Physidae were the macroinvertebrate families most related to levels of organic enrichment. Generally, the richness of families whithin any taxonomic group, showed very strong negative correlations with the organic pollution-associated gradient. The IASPT biotic index showed a stronger negative correlation with the gradient salinity-temperature than with the pollution gradient. Therefore, biotic assessments using this index must by done cautiously. In this weakness underlies the general tendency to overestimate the indicator value of good quality attributed to the families in the group EPT compared to that of the orders OCH. The IBMWP biotic index was, in great part, immune to the above bias thanks to the major contribution of family richness in the calculation of the index. Family richness was not correlated to the gradient salinity-temperature.
... Embora a composição do substrato seja semelhante dentro de cada microbacia, verifica-se que a velocidade da correnteza também varia e é determinante na distribuição das famílias, podendo explicar a necessidade de associação dos insetos aquáticos ao substrato. Obviamente, velocidade da água apresenta uma força física direta aos organismos, mas esta variável também afeta outros fatores dentro do rio como composição do substrato, distribuição de nutrientes, e teor de oxigênio (CORKUM, 1989;WIBERG-LARSEN et al., 2000). Algumas variáveis ambientais como, nutrientes, sedimento e hidrologia são mais influenciadas por características de escala regional, enquanto que outras variáveis são mais controladas na escala local (e.g. a cobertura vegetal em um local) (ALLAN et al., 1997). ...
Neotropical rivers suffer effects of human actions. Conservation measures are based on data from other regions because few studies in this region and limnology knowledge. But it's often inability to realize differences in the environmental variables answer at different scales about aquatic communities. This study aimed: to know aquatic insects richness in a neotropical watershed to check the environmental variables influence on the distribution of aquatic insects families in four tributaries of this microbasin and to check the rate distribution pattern of aquatic insects families between different rivers orders and different microbasins, according to environmental and spatial variables influence. We found 9,135 individuals belonging to 26 macroinvertebrates families. The communities structure were differed between microbasins. The aquatic insects families were influenced by different spatial and environmental variables in each microbasin.
... Different parameters such as stream size, altitude, slope and water velocity have been related to the distribution of caddisfly species (e.g. Wiberg-Larsen et al. 2000;Resh et al. 2002;Schmera and Erõs 2004;Bonada et al. 2005;Feio et al. 2005a, Á lvarez-Troncoso et al. 2015. Apart from these, one of the most important is substrate type (Feio et al. 2005a(Feio et al. , 2005b. ...
We analysed the microhabitat preferences of caddisfly species in four rivers in north-western Spain. In each river, we sampled five sites with different types of substrate. These sites were characterised in situ according to the predominant material type (macrophytes, moss, pebbles and sand). A one-way ANOVA was used to test for significant differences in species abundance among substrates, and a nested ANOVA was used to test for significant differences in physical and chemical variables among rivers and sampling sites. A similarity percentage-species contribution analysis was performed to estimate the contribution of each species to the characterisation of each substrate. We observed significant differences in the abundance of seven species (Drusus bolivari, Glossosoma privatum, Larcasia partita, Micrasema longulum, M. servatum, M. gr. moestum and Sericostoma sp.) among substrates, confirming that these species have substrate preferences. According to similarity percentage-species contribution, the species that contributed most to differences were as follows: for sand, Sericostoma sp.; for macrophytes, Rhyacophila adjuncta, Hydropsyche ambigua, Sericostoma sp.; for moss, Micrasema gr. moestum, M. servatum, M. longulum, Hydropsyche tibialis and R. adjuncta; and for pebbles, Sericostoma sp., Larcasia partita and H. tibialis. These preferences can be explained by the fact that different species use different materials from the substrate to build their cases and also as a source of stability, protection and food.
... Embora a composição do substrato seja semelhante dentro de cada microbacia, verifica-se que a velocidade da correnteza também varia e é determinante na distribuição das famílias, podendo explicar a necessidade de associação dos insetos aquáticos ao substrato. Obviamente, velocidade da água apresenta uma força física direta aos organismos, mas esta variável também afeta outros fatores dentro do rio como composição do substrato, distribuição de nutrientes, e teor de oxigênio (CORKUM, 1989;WIBERG-LARSEN et al., 2000). Algumas variáveis ambientais como, nutrientes, sedimento e hidrologia são mais influenciadas por características de escala regional, enquanto que outras variáveis são mais controladas na escala local (e.g. a cobertura vegetal em um local) (ALLAN et al., 1997). ...
Neotropical rivers suffer effects of human actions. Conservation measures are based on data from other regions because few studies in this region and limnology knowledge. But it's often inability to realize differences in the environmental variables answer at different scales about aquatic communities. This study aimed: to know aquatic insects richness in a neotropical microbasin to check the environmental variables influence on the distribution of aquatic insects families in four tributaries of this microbasin and to check the rate distribution pattern of aquatic insects families between different rivers orders and different microbasins, according to environmental and spatial variables influence. We found 9,135 individuals belonging to 26 macroinvertebrates families. The communities structure were differed between microbasins. The aquatic insects families were influenced by different spatial and environmental variables in each microbasin.
... Different parameters such as stream size, altitude, slope and water velocity have been related to the distribution of caddisfly species (e.g. Wiberg-Larsen et al. 2000;Resh et al. 2002;Schmera and Erõs 2004;Bonada et al. 2005;Feio et al. 2005a, Á lvarez-Troncoso et al. 2015. Apart from these, one of the most important is substrate type (Feio et al. 2005a(Feio et al. , 2005b. ...
... With the exception of significantly greater a-diversity in downstream sites -a pattern which has been confirmed by numerous previous studies (e.g. Malmqvist and Hoffsten 2000;Wiberg-Larsen et al. 2000)-our results contradicted our predictions. For example, the decrease in diversity was similar between stream order groups along the impact gradient, and headwater streams did not generally exhibit greater bdiversity than downstream sites. ...
The ongoing degradation of freshwater habitat quality and subsequent losses of biodiversity is alarming. One key to successful freshwater management is to understand how different scale-dependent diversity components (i.e. γ-, α- and β-diversity) change along present-day anthropogenic impact gradients. We used macrophyte, fish and macroinvertebrate data from Danish lowland streams to investigate whether (1) high connectivity in reaches situated in lower parts of the stream network (downstream sites) generates high α-diversity, while dispersal limitation and high habitat heterogeneity across the more isolated upper reaches (headwater sites) generate high β-diversity, (2) γ-, α- and β- diversity decrease with increasing hydromorphological impact and (3) high connectivity in downstream reaches buffers against impacts on biodiversity. Results showed that α-diversity was higher in downstream sites, while headwaters did not exhibit greater β-diversity. We observed a significant but relatively small decline in α-diversity with increasing hydromorphological impact, while β-diversity changed more unpredictably along the gradient. There was no clear mitigating effect in downstream reaches as the reduction in diversity from low to high impacted sites was similar between upper and lower reaches. We suggest that the results, which generally contradicted our predictions, partly reflect the intense historic and present land use in the region leading to an isolation of available source communities and a diminished regional species pool. The importance of having a landscape perspective in conservation management in highly impacted regions is emphasised because it is a prerequisite for recolonisation and population stability over time.
... Mykra et al. (2007) found that stream size was one of the two environmental variables that consistently explained assemblage structure at all landscape scales in a study of streams in Northern Finland. Others have shown that when streams are reclassified by size very distinct communities are found (Malmqvist and Maki 1994, Wiberg-Larsen et al. 2000, Mykra et al. 2004). ...
... We show that caddisfly densities and assemblages varied between study reaches and streams and that habitat variables associated with microdistributions varied with species. Other studies have similarly shown that hydrological and food-source variability associated with stream size can generate assemblage and species richness differences between streams (Wiberg-Larsen et al. 2000, Meyer et al. 2007) and that local-scale habitat variables (e.g., substrate composition, food type, flow patterns) can strongly relate to caddisfly assemblage structure (Feminella and Resh 1991, Urbani et al. 2005, Gombeer et al. 2011). The preliminary findings reported here, coupled with information from sampling efforts in similar streams over broader time frames, should enable us to better understand how changing reach characteristics might generate predictable patterns in local caddisfly assemblages in Mediterranean-climate streams. ...
sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne's Terms of Use, available at www.bioone.org/page/ terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. Physical and biogenic habitat characteris-tics interact to affect microdistributional vari-ability and phenotypic composition of larval stream caddisfly assemblages. For example, species residing in slow-flowing areas where fine sediments (sand grains) or benthic organic matter (BOM: leaves, twigs, detritus) accumu-late often build cases from these materials (Eggert and Wallace 2003) in high-flow intol-erant shapes (e.g., Heteroplectron—Anderson et al. 1984). In contrast, species residing in fast-flowing areas with coarse, stable substrates Western North American Naturalist 73(3), © 2013, pp. 261–269
... cent research in the study of communities and complex systems has shown that the newer analytical methods of non-linear artificial intelligence (Park et al . 2003a,b) can characterize species assemblages as components of ecological communities extremely well. Examples of such studies are the analysis of the Trichoptera assemblage in Danish streams (Wiberg-Larsen et al . 2000), the assessment of the Luxembourg river water quality using diatom assemblages (Gevrey et al . 2004), the investigation of macroinvertebrate assemblages in Brazil (Buss et al . 2004) and the prediction and spatial mapping of New Zealand freshwater fish and decapod assemblages (Joy & Death 2004). ...
Summary • The many thousands of potential invasive species pose one of the greatest threats to global biodiversity world-wide. In this study we propose that assemblages of well-known global invasive pest species, irrespective of whether they arise by anthropogenic means, are non-random species groupings that contain hidden predictive information. Such information can assist the identification and prioritization of species that have the potential to pose an invasive threat in regions where they are not normally found. • Data comprising the presence and absence of 844 insect pest species recorded over 459 geographical regions world-wide were analysed using a self-organizing map (SOM), a well-known artificial neural network algorithm. The SOM analysis classified the high dimensional data into two-dimensional space such that geographical areas that had similar pest species assemblages were organized as neighbours on a map or grid. • The SOM analysis allowed each species to be ranked in terms of its risk of invasion in each area based on the strength of its association with the assemblage that was characteristic for each geographical region. A risk map for example species was produced to illustrate how such a map can be compared with the species’ actual distribution and used with other information, such as the species’ biotic characteristics and interactions with the abiotic environment, to improve pest risk assessments further. • Synthesis and applications. This study presents a new approach to the identification of potentially high-risk invasive pest species based on the hypothesis that global insect pest assemblages are non-random species groupings that can be subjected to traditional community analysis. A well-known data mining and knowledge discovery method for high dimensional data, SOM, was used to determine pest species assemblages for global regions. Species were ranked according to their potential for establishment based on their strength of association with the species assemblage that characterizes a particular region. Such an analysis can then be used to support additional risk assessment of potential invasive species, giving invasive species researchers, conservation managers, quarantine and biosecurity scientists a means for prioritizing species as candidates for further research. Journal of Applied Ecology (2006) 43, 858–867 doi: 10.1111/j.1365-2664.2006.01202.x
... La presencia de plecópteros para tres ríos muestreados (Nuestra Señora, La Picón y La Corcovada), permite observar que características ambientales similares, como el tipo de sustrato, velocidad de la corriente, el pH, oxígeno disuelto, la disponibilidad del alimento y la conservación de bosques ribereños (observación personal), permiten: el suministro de materia orgánica y el aporte de nutrientes para el hábitat de los insectos (Wiberg-Larsen et al. 2000), la colonización y establecimiento de poblaciones de plecópteros y de insectos acuáticos en general (vidal & Membiela 1993, Mavri et al. 2000) y el estudio de la buena calidad ecológica (Miserendino 2000) del cauce. ...
Population status of insects of Plecoptera order in Sierra Nevada National Park in Venezuela and its implications for conservation planning. Longitudinal distribution of Plecoptera species were examined along the Sierra Nevada National Park in the Andean region of Merida State, Venezuela. PNSN is one of the largest protected areas and consists of two major sub-basins. Quantitative samples were collected in 7 river tributaries along the PNSN from February to May of 2009, and a total of 135 individuals and 4 species of the genus Anacroneuria were collected. Only three rivers (Nuestra Señora, La Picón y Corcovada) found the presence of stoneflies, the principal component analysis show that the characterization of habitat, current velocity, dissolved oxygen and the absence of human disturbance sources of influence in a suitable habitat for populations. Stoneflies are endangered or have become extinct throughout much of its range due to human activities. Conservation plans must be implemented urgently, in order to avoid recreational areas and/or economic in vicinity thereof. Rev. Biol. Trop. 58 (4): 1299-1310. Epub 2010 December 01.
... Lowest diversity and equitability were recorded at the Kozjak-Milanovac barrier, however, generally no marked differences between sites were observed (Table 2). A wide range of food resources and high concentration of organic matter compared to downstream barriers (Horvatinčić et al., 2006;Špoljar et al. 2007), and the variety of microhabitats are probably the main reasons for highest population density and species richness at Labudovac barrier (Waringer, 1996;Wiberg-Larsen et al., 2000;Habdija et al., 2004;Miliša et al., 2006;Šemnički et al., submitted). Kučinić, 2002 andPhilopotamus variegatus (Scopoli, 1763). ...
Caddisflies were collected in the Plitvice Lakes NP during 2008 using
emergence traps at 3 locations at tufa barriers. A total of 2217 specimens,
belonging to 44 species, 27 genera and 12 families were recorded during this
study. Six species, Hydroptila cognata, Hydroptila occulta, Ecnomus tenellus,
Potamophylax luctuosus, Beraeodes minutus and Ceraclea annulicornis are
new to the caddisfly fauna of the Plitvice Lakes NP. The highest number of
species and individuals were collected at Labudovac barrier and diversity was
highest at Labudovac and Novakovića Brod barriers. Emergence peaks for the
majority of species at tufa barriers were recorded in the summer. The longest
emergence period of seven months was recorded for Rhyacophila dorsalis
plitvicensis and Wormaldia subnigra. Emergence patterns of the most abundant
species are in accordance with results of previous studies in the Plitvice Lakes
NP. However, discrepancies in emergence patterns compared to their typical
emergence patterns could be linked with the specific composition of caddisfly
communities at tufa barriers.
... Indeed, the longitudinal gradient and the mineralization gradient are such variables that influence undoubtedly the species composition of invertebrate assemblages (e.g. Illies and Botosaneanu, 1963;Vannote et al., 1980;Wright et al., 1984;Botosaneanu, 1988;Wasson, 1989;Wiberg-Larsen et al., 2000;Lorenz et al., 2004). ...
Introduced organisms are seen as one of the greatest threats to resource sustainability worldwide, and aquatic macroinvertebrates are regarded as good indicators of the health of water resources. To explore these two perspectives, the responses of macroinvertebrate faunas to native and introduced fishes in three headwater tributaries of the Keiskamma River system, South Africa, were examined by comparing potential indicator communities in reaches considered to be fishless, reaches invaded by introduced salmonid species, and reaches containing native fishes. Patterns in the macroinvertebrate faunal assemblage data were driven strongly by season and flow rate, and less strongly by the presence of insectivorous fishes and biotope availability, a finding in parallel with several similar studies from the region. This affirms that aquatic macroinvertebrate faunas are responsive indicators of both environmental and biotic factors and leaves room for further studies to resolve the effects of non-native fish in the Keiskamma River system and other similar systems from South Africa.
Intermittent rivers, lotic habitats that cease to flow during the dry periods of the year, make up a large proportion of the world’s inland waters and are an important source of water in arid regions such as the Mediterranean. Yet, water resources and riparian habitats in the Mediterranean regions are under diverse anthropogenic pressures, including land-use change. Odonata are widely used as a valuable tool for assessing freshwater ecosystems. Hence, with the aim of inspecting the conservation value of intermittent rivers in the Mediterranean based on the assemblages they support, we studied Odonata adults at four intermittent Mediterranean rivers in the Dinaric Western Balkans ecoregion with respect to the surrounding land-cover heterogeneity. We analyzed several diversity and conservation indices and recorded significant differences in Odonata species richness and Croatian Conservation Odonatological index among the studied rivers. Our findings showed that land use, as a long-term moderate anthropogenic impact, can enhance land-cover heterogeneity and in some cases even lead to increased Odonata diversity in intermittent rivers in the Mediterranean. Intermittent rivers provide habitat for several threatened Odonata species, suggesting the importance of Odonata in planning the conservation activities in these vulnerable ecosystems.
1. In this publication, evolutionary interpretations of the larval, pupa, adult stages, and cases of order Trichoptera in the world literature were compiled. 2. The environmental conditions in which ancestral Trichoptera taxa live were also compiled from the publications. 3. The opinions defended in the publications were listed in temporal order. Studies which are carried out using the molecular techniques were compared with other studies and mentioned which opinions were supported by the studies using molecular techniques.
The caddisfly community composition and structure were studied in the Mediterranean (i.e., central part of Herzegovina) and the temperate (i.e., Central Bosnia) regions of the country which differ considerably regarding the climate, hydrology, geomorphology, and vegetation. In both studied areas, four rivers with seven sampling sites each were selected for light-trapping of adult caddisflies during a one-year period. A total of 97 species were collected (i.e., 52 in Herzegovina during 2003 and 67 in Central Bosnia during 2004) and seven of them are first records for Bosnia and Herzegovina. Marked differences in caddisfly community composition and structure between the two regions were found and confirmed by a cluster analysis of comparable river sites. These differences could be primarily linked to observed variability in environmental factors. Also, distinct phenological patterns of caddisflies were found in the Mediterranean and temperate parts, respectively, and these were further analyzed in detail for the five most abundant common species. For the populations in Central Bosnia, generally later and shorter periods of flight were recorded. Therefore, we tested the influence of meteorological parameters (night air temperature during the light-trapping, and monthly values of air temperature, precipitation, humidity, cloudiness, and wind speed) on flight activity and periodicity of caddisflies in both regions. Air temperature proved to be the most important of tested parameters influencing caddisfly flight patterns (rs > 0.87 for monthly values and rs > 0.44 for air temperatures during light-trapping; p < 0.001). Thus, temperature during light-trapping and minimum monthly values seem to be important for the flight of caddisflies, since these values were significantly different (p < 0.001 and p < 0.05, respectively) in the two regions of the country. Additionally, in this paper we will discuss some implications for conservation of caddisflies due to the predicted climate change.
Trichoptera have been utilised infrequently in palaeoecological studies despite their value as environmental indicators of freshwater habitat structure and quality, via their aquatic larvae, and catchment macroclimate conditions, via the aerial adults. Two sites, dated ca. 11 600 14C yr BP, in the middle reaches of the River Trent (England) supported caddisfly (Trichoptera) assemblages indicative of a dynamic braided river with extensive floodplain development. At the first, Barrow-upon-Trent, the caddisfly assemblage was dominated by taxa indicative of a medium to large gravel-bed river (Lepidostoma hirtum, Micrasema setiferum and taxa from the family Hydropsychidae). At the second site, Hemington, the caddisfly fauna was dominated by taxa from the families Limnephilidae and Phryganeidae. These usually occur in slow flowing and standing waters and are indicative of cut-off channels on the floodplain. Micrasema setiferum does not occur in the contemporary UK fauna and has a modern distribution across central Europe and Fennoscandia. A gridded climatology extracted for those geographical areas where M. setiferum occurs today indicated a greater degree of continentality than currently prevailing in the Trent catchment. The value of Trichoptera in palaeoecological studies is explored and a model of channel evolution for the River Trent is presented based on caddisfly data. Copyright © 2003 John Wiley & Sons, Ltd.
Introduction The understanding of distribution patterns in communities is one of the main aims in ecology (Begon et al. 1996). Several factors, measured at multiple-scale, influence these distribution patterns (Poff 1997). The relative effect may vary according to the spatial scale of the study. In large-scale studies history may be important, whereas in small-scale studies patterns can be explained by environmental variables alone (Townsend et al. 2003, Urbanič 2004). The main objectives of this study are to determine environmental key variables for caddisfly distribution and to identify the major species groups typical for rivers of the Hungarian lowland in Slovenia. Study area The study rivers are located in eastern Slovenia, which, according to Illies' (1978) set of ecoregions lies in ecoregion 5 – the Dinaric Western Balkan. However, for the needs of the implementation of the Water Framework Directive (EU, 2000) new delineations of the ecoregions were made in Slovenia (Urbanič 2005). According to this new system, which was used in this study, the eastern part of Slovenia belongs to ecoregion 11 (Hungarian lowland).
In 2004 I put together three unpublished bibliographic volumes concerning correspondence analysis. These papers provide an extensive overview of more than 1300 articles that explore the diversity of mathematical and practical issues of correspondence analysis. I conceed that, with the increasing availability of online databases, more extensive bibliographies are now available. This bibliography has the references listed by year of publication.
Macroinvertebrate assemblages and environmental variables were evaluated at 45 stream sites throughout the Puget Sound Basin, Washington, USA. Environmental variables were measured at 3 spatial scales: reach, local, and whole watershed. Macroinvertebrate distributions were related to environmental variables using canonical correspondence analysis to determine which variables and spatial scales best explained the observed community composition and to identify biota–land cover optima. The calculation of a biota–land cover optimum was a 2-step process. First, an individual taxon's optimum was estimated for a particular land cover by weighting the mean value for that land cover by the abundance of that taxon at all sites. Second, the biota–land cover optimum was determined as the point at which the greatest numbers of taxa, at their calculated optima, appeared for a particular land cover. Sampling reaches were located on streams in watersheds with varying levels of forest, agriculture, and urban/suburban land cover that represented the full range of physical conditions typically found in Puget Sound streams. At the reach scale, taxa composition was correlated with conductivity and mean velocity. At the local and whole-watershed scales, taxa composition was correlated with % forest and agricultural land cover and % forest and bedrock land cover, respectively. For all of the scales, the dominant environmental variables represented an anthropogenic gradient. There was little difference in the amount of variability explained by each spatial scale. At the local-watershed scale, a biota–land cover optimum of ∼80 to 90% forest land cover was identified. The total number of taxa at their optima declined rapidly as forest land cover within the local scale declined below 80 to 90%. At the whole-watershed scale, a biota–land cover optimum of 70 to 80% forest land cover was identified. The total number of taxa at their optima declined rapidly as forest land cover within the whole watershed declined below 70 to 80%. Our results suggest that macroinvertebrates can be used both as quantitative indicators of environmental conditions at multiple scales and indicators of land cover optima. Further examination of these optima could be used to establish priorities for conservation and restoration efforts.
Analyses of a sediment core from the Great Belt documented the local presence of fluvial deposits. The sediments consisted of silt, clay, sand and organic detritus and they contained macroscopical remains of a mixture of terrestrial, telmatic, lacustrine and fluvial plants and animals. Most noteworthy was the abundance of remains of caddis fly larvae, totalling at least 24 species, which were dominated by fluvial species. Thus, filter-feeding hydropsychids made up approximately 95% out of 1496 identified specimens, the dominating species being Hydropsyche contubernalis and H. pellucidula. The present-day requirements of the recorded species point to a fairly fast-flowing river, at least locally, with areas of stones (some with moss growth) and gravel, but also to more slowly-flowing parts with sand, fine and coarse detritus. This river may have been considerably larger than any present-day Danish river. It appears that the fluvial deposits formed locally in connection with flooding of the area south of the core position. AMS radiocarbon dating shows that the sequence was deposited very rapidly during the early Holocene, about 10650 to 10250 cal. years BP. The occurrence of the lentic Leptocerus tineiformis points to a climate at least as warm as today.
Fishes of small streams in Ottawa County, Oklahoma, were collected by seine from July 2004 through October 2005 to provide base-line data on species occurrences in Tar Creek and surrounding watersheds. Nine sites within the study area have been receiving mine drainage contaminated with iron, zinc, lead and cadmium for at least three decades fol- lowing the cessation of mining in the Tri-State Mining District of Oklahoma, Kansas, and Missouri in the 1960s. No such known contamination exists for the remaining sampling sites which serve as "controls" for any future changes in fishes at the polluted sites. Fifty- three collections were made at 10 sites throughout Tar Creek watershed, and 26 collec- tions were made on surrounding watersheds at sites on Coal, Cow, Little Elm, Hudson, Mud, and Four-mile creeks in Ottawa County. A total of 34 species and hybrid sunfish representing ten families were collected. Faunal composition of impacted streams was compared with non-impacted streams. Species richness, corrected for habitat size, was significantly lower in impacted sites than in non-impacted sites. As planned treatment systems for the mine drainage are implemented, the information in this report will allow evaluation of any changes in fish communities. © 2006 Oklahoma Academy of Science.
We define disturbance in stream ecosystems to be: any relatively discrete event in time that is characterized by a frequency, intensity, and severity outside a predictable range, and that disrupts ecosystem, community, or population structure and changes resources or the physical environment. Of the three major hypotheses relating disturbance to lotic community structure, the dynamic equilibrium hypothesis appears to be generally applicable, although specific studies support the intermediate disturbance hypothesis and the equilibrium model. Differences in disturbance frequency between lentic and lotic systems may explain why biotic interactions are more apparent in lakes than in streams. Responses to both natural and anthropogenic disturbances vary regionally, as illustrated by examples from the mid-continent, Pacific northwest, and southeastern United States. Based on a generalized framework of climatic-biogeochemical characteristics, two features are considered to be most significant in choosing streams for comparative studies of disturbance: hydrologic regimes and comparable geomorphology. A method is described for quantifying predictability of the hydrologic regime based on long-term records of monthly maximum and minimum stream flows. Different channel forms (boulder and cobble, alluvial gravelbed, alluvial sandbed) have different responses to hydrologic disturbance from spates. A number of structural and functional components for comparing disturbance effects within regions and across biomes are presented. Experimental approaches to studying disturbance involve spatial-scale considerations, logistic difficulties, and ethical questions. General questions related to disturbance that could be addressed by stream ecologists are proposed.
Habitat features and macroinvertebrate communities were surveyed in 66 predominantly upland streams throughout Wales and Scotland to assess the efficacy of riparian management (as buffer strips) in protecting stream resources during commercial forestry. Marginal habitat characteristics differed between streams with different riparian management. Streams with "harder' margins occurred where the banks were covered with either conifers or broadleaves. Streams with "softer' margins occurred in seminatural moorland, and where a buffer strip of moorland vegetation had been retained along the stream at the planting stage. Streams in conifer forest in which a riparian buffer strip had been cleared retrospectively were intermediate. For any given pH, aluminium concentrations were significantly higher in streams draining conifer catchments than in streams draining whole catchments of moorland or deciduous woodland. The taxon richnesses of Ephemeroptera, Plecoptera, Trichoptera and all taxa combined, in both riffles and margins, declined significantly with increasing acidity and aluminium concentration. Primary ordination axes form both habitats correlated with taxon richness, and hence also with pH and aluminium. However, there were significant effects on the ordination scores by riparian management, due mostly to reduced taxon richnesses in conifer sites without buffer strips. -from Authors
A revised check-list of the Trichoptera in Denmark, Sweden, Norway, Eastern Fennoscandia, the Faroes, and Iceland, reflecting current views on Trichoptera systematics, is given. A total of 242 species are recognized from these areas. The list includes 3 recently described species, and 6 species recorded as new to NW Europe, while 7 species are deleted due to synonymy, misidentification, or abnormality. Further, 38 additional regional records are included, as well as 1 deletion due to insufficient documentations. Annotations for new and rare species are provided. The hydroptilid Agraylea cognatella McLachlan, 1880 is retained as a valid species and the male genitalia of this species as well as the male genitalia of A. multipunctata Curtis, 1834 are figured.
The effects of iron compounds on the macroinvertebrate fauna were investigated in a Danish lowland river system (River Vidaa). As a result of industrial farming activities, water levels have been lowered and iron has leached from this system. Concentrations of annual average dissolved iron from 28 localities varied from about 0 to 32 mg Fe2+ l−1, while pH varied from 6.7 to 8.8. A negative correlation between numbers of taxa and concentration of dissolved iron is suggested. We collected 67 taxa of macroinvertebrates from sites where concentrations were below 0.2 mg Fe2+ l−1, however, between 0.2 and 0.3 mg Fe2+ l−1 an abrupt drop to 53 taxa was recorded. Taxa eliminated were primarily grazers feeding on biofilm. Elimination of taxa continued up to 10 mg Fe2+ l−1, where about 10 taxa were left. Numbers of individuals declined at concentrations >1 mg Fe2+ l−1. Ephemeroptera and Plecoptera were found only at low iron concentrations. The species found at highest iron concentrations belong to Tubificidae, Chironomidae and Tipulidae.
Water chemistry and benthic invertebrate communities of 100 headwater streams within 10 South Island, New Zealand, ecoregions were examined to assess the usefulness of ecoregions as a basis for stream classification. Water chemistry did not vary in a systematic manner among ecoregions and showed considerable variation within some of them. In contrast, invertebrate communities differed among ecore-gions in a much more consistent way. Taxonomic richness, numbers of endemic spe-cies, species dominance and summer faunal densities all differed among ecoregions, but little discrimination was possible using functional feeding groups. Stream faunas were generally similar between forested ecoregions, whereas the alpine (Southern Alps) ecoregion had the most distinct fauna. Geographically distinct areas that have been deforested and are dominated by tussock grassland and improved pasture now have very similar stream faunas with few regionally distinct elements present. Our results provide qualified support for the use of ecoregions as a basis for stream classi-fication in New Zealand.
1. Structure and diversity of the macroinvertebrate fauna were studied in relation to altitude and latitude among three groups of streams from Ecuador (lowland: 100–600 m, Central Valley: 2600–3100 m, páramo: 3500–4000 m), and one group from the temperate lowland region of Denmark. The streams in the four regions were comparable with regard to physical characteristics such as size, current and substratum.
2. In terms of faunal composition the Ecuadorian highland streams bore more resemblance to the Danish lowland streams than the Ecuadorian lowland streams. The greater similarity between the Ecuadorian highland and the Danish streams, however, was due to the large number of insect families in the Ecuadorian lowlands, many of which were not found in the other regions. Of ten physico-chemical parameters measured, maximum stream temperature explained by far the most variability in faunal composition.
3. The number of insect orders and families increased linearly with maximum stream temperature and therefore decreased with altitude and latitude. A compilation of literature data on insect richness and maximum water temperature from streams around the world confirmed this pattern, yielding a common linear relation for both temperate and tropical streams. This pattern may arise due to a direct temperature effect on speciation but is probably also related to geological history and the influence of climatic changes on stream ecosystems. We estimate that small, tropical, lowland streams have, on average, a two- to fourfold higher species richness than temperate lowland streams.
The species-area relationship of the island biogeography theory was calculated for macroinvertebrates in 22 coastal, adjacent streams. A z-value of 0.19 was obtained. The low z-value was probably a consequence of the short distances between streams as well as high dispersal rates. In addition, a cluster analysis based on the dissimilarity of species assemblages showed that stream size was of prime importance in categorizing the streams. To a smaller extent water quality affected the community structure in the streams.
Classification of streams and stream habitats is useful for research involving establishment of monitoring stations, determination of local impacts of land-use practices, generalization from site-specific data, and assessment of basin-wide, cumulative impacts of human activities on streams and their biota. This article presents a frame-work for a hierarchical classification system, entailing an organized view of spatial and temporal variation among and within stream systems. Stream habitat systems, defined and classified on several spatiotemporal scales, are associated with watershed geomorphic features and events. Variables selected for classification define relative long-term capacities of systems, not simply short-term states. Streams and their watershed environments are classified within the context of a regional biogeoclimatic landscape classification. The framework is a perspective that should allow more systematic interpretation and description of watershed-stream relationships.
We examined the relationship between habitat heterogeneity and benthic macroinvertebrate assemblages in thirty-two 2nd to 6th order wilderness streams in central Idaho. Twenty-one environmental measures were evaluated for each stream with their heterogeneity expressed in terms of coefficients of variation (CV's). Although the annual range in water temperature was greater in the larger (5th and 6th order) streams, most other habitat measures showed greater variation among smaller streams (2nd order) than larger streams. Mean habitat-CV's also were about 20% greater for smaller (2nd order) than larger (5th and 6th order) streams, suggesting a homogenizing influence of stream size on habitat heterogeneity. Multivariate analyses of the habitat measures clearly separated 5th and 6th order streams from ≤ 4th order streams, further indicating major environmental differences between larger and smaller stream systems. Multiple regression and canonical correspondence analysis revealed that some biotic properties, e.g. % shredders, were associated with stream size, reflecting longitudinal changes in food resource availability or annual variation in temperature, while others, e.g. Shannon's diversity, were more dependent on measures of within-reach habitat heterogeneity.
Thienemann (1954) observed that the number of species inhabiting a given locality is highest in areas which have persisted largely unchanged for a long time and are characterized by diverse and predictable (i.e., not deviating substantially from the long-term norm) environmental conditions. The rhithron (i.e., the habitat of cold, rubble-bottom streams often found in the middle and upper reaches of river systems) epitomizes the ideal running water environment for co-existence of many species (Illies, 1969), most of which are usually insects (Hynes, 1970).
Algal biomass, standing stocks of particulate organic matter (POM) and benthic invertebrate communities of 20 streams draining native forest, exotic conifer forest and tussock grassland catchments in the South Island, New Zealand, were examined in spring/summer 1994-95. Sixteen were forest streams, 8 in native and 8 in exotic forest, with 4 of each kind located on each side of the Main Alpine Divide and therefore in different climatic (including rainfall) zones. Chemistry of stream water reflected geographic location more strongly than forest type with western streams being slightly more acid and having lower ionic concentrations than those in the east. Algal biomass on stones in forest streams ranged from 7-51 mg chl · m-2, and regardless of forest type, appeared to be limited primarily by light and substrate stability. POM standing stocks were low (22-254 g AFDW m-2) and dominated by coarse materials (>13 mm) in both native and exotic forest streams. Benthic faunas of all stream groups were dominated numerically by Chironomidae and Ephemeroptera and contained similar numbers of species (35-40). However, differences in community composition were found between eastern and western streams, and these were greater than between forest types. Total invertebrate abundances were moderately low (2008-6083 m-2) and were significantly correlated with epilithic algal biomass. In contrast, correlations between invertebrate numbers and detrital biomass were weak, perhaps reflecting poor retention of riparian inputs. Our results support the view that forest type has little effect on stream benthic communities in the South Island, New Zealand, and that geographical factors (climate, location) are of greater importance.
In an upland fourth-order stream, the fauna dwelling on both natural and artificial stones was found to be highly correlated with stone surface area. The power function model provided a good description of the species-area relationship of the stones. For both types of stones, passive sampling was rejected as an explanation for the species-area relationship. The compilation of cumulative species richness, proceeding in order from the smallest area to the largest area and vice versa revealed a negative fragmentation effect. Groups of small stones harboured an impoverished fauna compared with large stones of the same surface area. Small stones did not harbour a distinctive fauna, but simply a sub-set of the species found on larger stones. To ascertain the significance of habitat diversity in generating the species-area relationship, grooves were cut into artificial stones and the fauna on grooved and ungrooved stones compared. Increased grooving on stones of identical surface area, increased both abundance and species richness significantly. Passive sampling, tested by rarefaction, did not satisfactorily explain this increase in species richness. Thus, for stream stones, habitat diversity appears to be a strong contributing factor for the increase in species richness with surface area.
The grazing caddis larva Glossosoma significantly depressed periphyton abundances. Greater numbers of other grazers (primarily the mayflies Ephemerella doddsi and Baetis spp.) were present on substrates where Glossosoma densities were reduced and periphyton abundances were not depressed. Resource exploitation by Glossosoma is the only mechanism contributing to reduced densities of other species. The physical presence of Glossosoma had no density- reducing effect beyond the effect of resource exploitation. -from Author
We propose that the Concept provides a framework for integrating predictable and observable biological features of lotic systems. Implications of the concept in the areas of structure, function, and stability of riverine ecosystems are discussed. -from Authors
SUMMARY1For Trichoptera occurring in two sites of the Upper Rhône River (France) we examine: (i) relationships among species traits; (ii) habitat utilization of Trichoptera species; (iii) the relationship between species traits and habitat utilization; (iv) trends of species traits in the framework of spatial–temporal habitat variability to test predictions of the habitat templet concept; and (v) trends of species richness in the framework of spatial–temporal habitat variability to test predictions of the patch dynamics concept.2Of the sixteen species traits selected, twelve have high correlation ratios for the seventy-five species used in this analysis; these traits are related to behavioural, morphological, or physiological aspects. Traits related to reproduction or life cycle have lower correlation ratios.3An ordination by species traits separates the five main families into three groups: (i) Hydropsychidae and Polycentropodidae; (ii) Hydroptilidae; and (iii) Leptoceridae and Limnephilidae. An ordination of the habitat utilization of the species in ten habitats indicates that the Hydropsychidae occur preferentially in the main channel, Hydroptilidae, Polycentropodidae, and Limnephilidae occur in backwaters or oxbow lakes, and the Leptoceridae are ubiquitous.4The Hydropsychidae exhibit a relationship between species traits and habitat utilization, i.e. they use similar habitat types with similar species traits. The species traits of the other four families are similar but their habitat utilization is quite different.5The Hydropsychidae occur in lowest spatial–temporal variability habitats and Limnephilidae in the highest. Therefore, net spinners and filterers are characteristic of habitats with a low spatial–temporal variability, whereas shredders and case makers using plant material are characteristic of habitats with high spatial–temporal variability. The trends in species traits show little agreement with trends predicted from the river habitat templet.6Trends of species richness in the framework of spatial and temporal variability do not follow the predictions of the patch dynamics concept because richness is similar in all superficial habitats. This implies that each habitat, in spite of large differences in their spatial and temporal variability, offers Trichoptera a similar but limited number of ecological niches.
An analysis of the relationships between lotic macroinvertebrates and environmental variables was earned out on material from 60 riffle sites in streams in northern Sweden The approach involved the use of TWINSPAN classification and canonical correspondence analysis on presence/absence data from two seasons (spring and autumn) Variables most strongly associated with distribution patterns of assemblages were drainage area, elevation, water quality in terms of alkalinity, colour and phosphate and the presence of macrophytes The significance of affinities of different species to these variables are discussed The eight clusters resulting from the TWINSPAN analysis could biologically be interpreted as classes of taxa related to stream size, chemical conditions and algae A multiple regression analysis for predicting species nchness using three independent variables, viz drainage area amount or organic matter, and discharge was constructed The results of the study could be used as a starting point for further work on the community organization of benthie stream assemblages
The species richness of stream benthic invertebrates was studied along a longitudinal profile of the Salmon River, Idaho. Species richness varied with stream size, being highest in midorder streams and lower in headwater and high order streams. This downstream shift in species richness conforms to the river continuum concept. Possible cause is associated with varying temperature regimes in the different-sized streams as well as other factors. Species richness also varied with season depending on stream size. Low order streams were more individualistic, probably because of a greater influence of local (terrestrial) environmental conditions, but showed a higher richness in summer than in autumn than in summer. Other community-level indicators, eg relative immigration rate and extinction rate, also showed seasonal differences. Different macroinvertebrate community types having characteristics of either nonequilibrium (density-independent, opportunistic) or equilibrium conditions can be found in streams from the same drainage basin depending on location along the river continuum and time of the year. -from Authors
1. Studies on the zonation of benthic fauna in fourteen streams situated in a variety of latitudes from Alaska to New Zealand have been evaluated.
2. We suggest that physical characteristics of flow (‘stream hydraulics’) are the most important environmental factor governing the zonation of stream benthos on a world-wide scale.
3. From the source to the mouth of a stream, zones of transition in stream hydraulics' occur, to which the general pattern of stream invertebrate assemblages can be related. In these zones benthic community stability and resilience must be different from those upstream and downstream of the hydraulic transition zones.
Predatory net-spinning larvae of the caddisfly Plectrocnemia conspersa were studied in a small fishless stream to determine any impact of this predator on the abundance of its prey. Significant predator impacts were observed in winter only, and results varied with prey taxon. Prey exchange rates were manipulated. Predator impacts were most pronounced at low exchange rates, and were less distinct at high exchange. The effect of mesh size on prey exchange varied among taxa in relation to species-specific morphology and dispersal behaviour. Experimental detection of predator impacts therefore appears to be highly dependent on both prey mobility and spatial heterogeneity. A graphical model is presented to illustrate how the detection of predation effects inside enclosures may be influenced by prey mobility. The continuous redistribution of prey populations may be an important factor to include in models of community structure and organization in heterogenous environments with mobile species, such as streams. -from Authors
Six physical and hydrological variables were used to assess environmental stability at sites on 10 contrasting streams in the Southern Alps of New Zealand. Five of the streams were spring-fed and initially designated ''stable'', and the others, which were predominantly catchment-fed, were designated ''unstable''. At each site, depth, current velocity, and water temperature were measured monthly for 19 mo, and the distances moved by marked stones in three size groups were determined over 18 mo. Stone invertebrate communities were sampled at each site at three monthly intervals. Tractive force measurements and the Pfankuch stability index were also calculated. Monthly depth and current variability, temperature range, Pfankuch stability scores, and substrate movement were all greater at the five ''unstable'' sites, but the rank order of sites obtained with each measure was not consistent. Tractive force was the only stability measure that did not differ significantly between ''stable'' and ''unstable'' streams. Principal components analysis (PCA) was used to combine values for all six variables into single multivariate instability scores (PCA scores for Axis 1). These scores were strongly correlated with all individual stability variable scores with the exception of those for tractive force. We suggest that the effects of environmental stability on community structure should be assessed using a measure that is representative of all the physical characteristics at a study site, and we believe the multivariate instability score goes some way towards achieving this. Such a procedure, however, does not negate the use of individual measures for examining specific environmental relationships as well. Although differences in the persistence of some community characteristics could be detected using the initial ''stable/unstable'' groups, others could only be seen when plotted on a more continuous scale using the multivariate instability scores. Persistence of the dominant invertebrate taxa was high at all sites, but persistence of the entire fauna was higher at the stable sites.
Quantitative geomorphic methods developed within the past few years provide means of measuring size and form properties of drainage basins. Two general classes of descriptive numbers are (1) linear scale measurements, whereby geometrically analogous units of topography can be compared as to size; and (2) dimensionless numbers, usually angles or ratios of length measures, whereby the shapes of analogous units can be compared irrespective of scale.
Linear scale measurements include length of stream channels of given order, drainage density, constant of channel maintenance, basin perimeter, and relief. Surface and crosssectional areas of basins are length products. If two drainage basins are geometrically similar, all corresponding length dimensions will be in a fixed ratio.
Dimensionless properties include stream order numbers, stream length and bifurcation ratios, junction angles, maximum valley-side slopes, mean slopes of watershed surfaces, channel gradients, relief ratios, and hypsometric curve properties and integrals. If geometrical similarity exists in two drainage basins, all corresponding dimensionless numbers will be identical, even though a vast size difference may exist. Dimensionless properties can be correlated with hydrologic and sediment-yield data stated as mass or volume rates of flow per unit area, independent of total area of watershed.
Adult body size and fecundity of several species of hemimetabolous aquatic insects were shown to depend largely on thermal conditions during larval growth. We suggest that an "optimum" thermal regime exists where adult size and fecundity are maximized; temperature regimes warmer or cooler than the "optimum'' result in small and less fecund adults. Two hypotheses concerning river water temperatures and size variation of adult insects are described. First, maximum adult size reflects an equilibrium between several developmental processes that appear highly temperature dependent, viz., (i) the rate and duration of larval growth, and (ii) the specific time in larval development that adult structures begin maturing and the rate of this maturation process. Second, a species distribution both locally within drainage systems and over a large geographic area is limited, in part, by lowered fecundity as adult size gradually diminishes in streams of increasingly cold or warm temperature cycles. The importance of riv...
1. Biogeographical and on-site. hydrological variables were evaluated to determine spatial distribution of benthic invertebrate assemblages at 100 river sites in northwestern North America.
2. Results of cluster analysis suggested that the river sites comprised sixgroups (A-F), each supporting a characteristic invertebrate assemblage.Distinct groups were best represented by abundant Tricorythidae (C), Amphipoda (F), Rhyacophilidae and Systellognatha (E), and Elmidae and Hydroptilidae (A). Brachycentridae (B) and Oligochaeta (D) were widespread throughout the study area.
2. Both biogeographical and hydrological features contributed to the correct classification of site groupings characterized by distinctive fauna. However, biogeographical features were more useful than variables measured at the river site in discriminating among the site groupings.Groups C and F were most prevalent within the Hudson Bay drainage.Groups A, C and F were typically located within plains; group E sites were in mountainous regions.
4. The hydrological variables most useful in delineating site groupings were mean current velocity and mean depth. Slow, deep waters characterized amphipod sites; shallow, fast flowing waters occurred at Rhyacophilidae Sysellognatha sites.
5. Results substantiate previous views of a strong association between benthic invertebrates in small rivers and the terrestrial biome through which the river flows.
1. The relationships between three habitat scales and lotic invertebrate species composition were investigated for the 15 540 km2 Yakima River basin in south-central Washington, U.S.A.
2. The three spatial scales were sample (the sampled riffle), reach (a length of ten–twenty stream widths) and segment (a length of stream of nearly uniform slope and valley form having no change in stream order).
3. Physical variables were highly correlated between scales and expressed a relationship between altitude, basin form and small-scale physical structure.
4. Multiple discriminant function analyses indicated that segment- and reach-scale variables discriminated among species-defined groups better than sample-scale variables.
5. Species composition varied along a complex altitudinal gradient of changing basin form and resultant land use.
6. There was no clear relationship between species richness and altitude on a site basis. However, when viewed at the basin scale, maximum richness was observed at the transition between montane and valley sites.
Field experiments were conducted to assess the effects of different population densities of the herbivorous caddisfly Helicopsyche borealis on periphyton biomass and on its own growth rate in Big Sulphur Creek, a third-order stream in northern California, USA. Stream enclosures were used to vary grazer density from one-eighth to twice natural density (1/8X–2X) in two experiments (35 d and 60 d), which spanned the period of most rapid larval growth. Periphyton biomass and chlorophyll a were inversely related to grazer density. Grazer densities of 1/8X–1/2X moderately reduced periphyton when compared to an ungrazed control, whereas densities of 1X–2X greatly depleted periphyton. The growth rate of H. borealis larvae declined with increasing larval density. Growth rate was highest at densities of 1/8X–1/2X; larvae grew more slowly at 1X and showed no growth at 2X. Weekly supplementation of periphyton to 1/4X, 1X, and 2X densities significantly increased the final body mass of larvae at 1X and 2X (by 26% and 50%, respectively, compared to unsupplemented larvae) but did not change the body mass of larvae at 1/4X. These results suggest that periphyton is a limiting resource in Big Sulphur Creek and that H. borealis larvae compete exploitatively for that resource. Intraspecific competition may be an important, but often overlooked, feature of many herbivore populations in streams.
Aspects of life-history, oviposition and microdistribution within beds of Ranunculus penicillatus var. calcareus (R. W. Butcher) C.D.K. Cook are considered. Brachycentrus subnubilus Curtis has one generation each year, with five larval instars. Larvae favour sites beneath the weedbeds for most of the year, migrating to more exposed areas in the spring to pupate. Pupation, emergence, oviposition and eclosion are completed in just over two months. Eggs are usually laid on submerged marginal vegetation but any semi-submerged object may be utilized. Larvae appear to disperse mainly as first instars; in this they are likely to be seriously affected by weedcutting activities. Initial development is rapid to fourth instar. Larvae overwinter as fifth instars. Sex ratios show a predominance of males.
A survey was carried out at 156 sites, situated in streams in the province of Overijssel (The Netherlands), to describe the macroinvertebrate assemblages and their environments. Fifty-six environmental variables were measured once at each sampling site. The main aim was to describe a typology of stream for this region.
Different multivariate analysis techniques (clustering and ordination) were used in combination with ecological information on individual taxa to derive and describe site groups in terms of taxonomic composition and mean environmental conditions. The resulting site groups were termed cenotypes.
Eleven cenotypes were distinguished. Differences between cenotypes were attributed to (combinations of) environmental key factors, namely, dimensions (width and depth), morphological (profile shape) and hydraulic stream characteristics, duration of drought and load of organic material.
The typology offers a basis to be used for regional stream management and nature conservation. Efforts to improve stream ecosystems should be directed at the physical and hydraulic conditions.
Typological studies are needed (especially in semi-natural landscapes) if we are to better understand, manage and conserve freshwater biota.
Why do larger areas have more species? What makes diversity so high near the equator? Has the number of species grown during the past 600 million years? Does habitat diversity support species diversity, or is it the other way around? What reduces diversity in ecologically productive places? At what scales of space and time do diversity patterns hold? Do the mechanisms that produce them vary with scale? This book examines these questions and many others, by employing both theory and data in the search for answers. Surprisingly, many of the questions have reasonably likely answers. By identifying these, attention can be turned toward life's many, still-unexplained diversity patterns. As evolutionary ecologists race to understand biodiversity before it is too late, this book will help set the agenda for diversity research into the next century.
Adult body size and fecundity of a number of hemimetabolous aquatic insects depend largely on thermal conditions during the
larval period. Small adults and reduced fecundity result when temperatures are either warmed or cooled with respect to more
optimal thermal conditions. Temperature apparently affects adult size by altering the larval growth rate and the timing and
rate of adult tissue development for each larva. The data suggest a new interpretation for the geographic distribution of
aquatic insects.
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mountain stream: can temporal/spatial separations
and food partitioning account for high diversity?
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Biological Structure of Forest Streams and Effects of Afforestation
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Friberg N. (1996) Biological Structure of Forest Streams and
Effects of Afforestation. PhD Thesis, National Environmental Research Institute, Silkeborg, Denmark.
Macroinvertebrate communities in Danish streams: the effect of riparian forest cover
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communities in Danish streams: the effect of riparian
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Pedersen), pp. 208±222. G.E.C. Gad, Copenhagen.
A typological approach of the distribution of caddis larvae in watercourses of Ardenne and adjacent areas (Belgium): Faunistic data and general aspects
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Stroot P. (1991) A typological approach of the distribution of caddis larvae in watercourses of Ardenne and
adjacent areas (Belgium): Faunistic data and general
aspects. Proceedings of the 6th International Symposium on
Trichoptera (Ed. C. Tomaczewski), pp. 75±80. Adam
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for canonical community ordination (Version 3.1). Microcomputer Power, Ithaca, NY.
Multivariate analyses of macrofaunal communities in Danish springs and springbrooks
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Lindegaard C., Brodersen K.P., Wiberg-Larsen P. &
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communities in Danish springs and springbrooks.
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Distribution of Chironomidae (Diptera) in the river continuum
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Chironomidae (Diptera) in the river continuum.
Chironomids: from Genes to Ecosystems (Ed. P. Cranston), pp. 257±271. CSIRO Publications, Melbourne,
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Die substratspezifische Verteilung der Ephemeroptera, Plecoptera und Trichoptera (Insecta) in einem sandigen Bach des Norddeutschen Tieflandes (Osterau, Schleswig‐Holstein)
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Speth S. & Bo È ttger K. (1993) Die substratspezifische
Verteilung der Ephemeroptera, Plecoptera und Trichoptera (Insecta) in einem sandigen Bach des Norddeutschen Tieflandes (Osterau, Schleswig-Holstein).
Limnologica, 23, 369±380.
Aquatic insect-substratum relationships. The Ecology of Aquatic Insects
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D.M. Rosenberg), pp. 358±400. Praeger Publishers,
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Substrate type and its value as a basis for the delimitation of bottom fauna communities in running waters
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basis for the delimitation of bottom fauna communities in running waters. Special Publication, Pymatuning Laboratory of Ecology, University of Pittsburg, 4,
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Caddis larvae as slaves of stream hydraulics
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Higler L.W.G. & Verdonschot P.F.M. (1991) Caddis
larvae as slaves of stream hydraulics. Proceedings of
the 6th International Symposium on Trichoptera (Ed. C.
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Rivers of the nordic Countries
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22: River and Stream Ecosystems (Eds C.E. Cushing K.W.
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Die substratspezifische Verteilung der Ephemeroptera, Plecoptera und Trichoptera (Insecta) in einem sandigen Bach des Norddeutschen Tieflandes
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